Known tripods for rescue purposes normally include a triangular base and three upright members extending from respective corners of the base to a support member generally above and offset from the base. The support member includes an attachment point for a pulley or other device which is used to support an object. During use of such a tripod, a forward edge of the base is positioned near to but spaced from an edge of a cliff or building with the support member positioned closest to the edge. The support member can be moved from a position inwards of the edge of the cliff, building etc. to an extended position beyond that edge by lifting a rearward corner of the base so as to rotate the whole tripod apparatus generally about its forward edge relative to the ground. The rearward corner of the base must then be secured in the elevated position while the object is being raised or lowered along the face of the cliff or building. Further, the rearward corner must be manually moved back into contact with the ground when the object is at a height above the surface on which the base is supported so as to cause the support member and, therefore, the object to move to a position inwards of the edge of the cliff, building etc. The object can then be lowered to the surface and disconnected from the tripod apparatus at a position spaced inwards from the edge of the cliff or building.
While such known tripod apparatus is useful, the need to move the whole of the apparatus so as to move the support member is inconvenient. Further, when the support member is in its extended position, the weight of the object being raised or lowered is only supported by the forward edge of the base which arrangement can be unstable. Further, it will be apparent that the procedure of raising and lowering the rearward corner of the base introduces a risk whereby, if the rearward corner of the base is accidentally released during the procedure, the apparatus is likely to topple over the edge of the cliff or building.
It would be desirable to provide an improved tripod apparatus which is able to move the support member between retracted and extended positions without necessarily having to move any part of the base of the tripod away from an initial position securely sitting on the ground.